Finding the Fourth Proportional to 1,160.66, 1,601.70 and 636.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,160.66 : 1,601.70 = 636.72 : x
2. Step 2: Convert to fraction form
   1,160.66/1,601.70 = 636.72/x
3. Step 3: Cross multiply
   1,160.66x = 1,601.70 × 636.72
4. Step 4: Simplify right side
   1,160.66x = 1,019,834.42
5. Step 5: Solve for x
   x = 1,019,834.42/1,160.66
6. Step 6: Final answer
   x = 878.67